The presence of salts, and other unwanted substances, in soils, such as agricultural soils, and their adverse effects on plant proliferation, have long been recognized. The salts, such as chlorides, carbonates and sulfates of sodium, potassium, calcium and magnesium, are often already present in the soil, prior to planting. In addition, in some cases, salts are introduced into the soil through the use of irrigation water.
In general, the effect of salts on plants is indirect. In this regard, the salts adversely affect osmotic water potential with a resulting reduction in uptake of water by germinating seeds and the roots of established plants. The presence of salts in soils can result in a fewer number of seeds becoming properly established. Also, there can be an undesirable delayed rate of seed establishment, as well as an impairment in the growth of established plants.
Due to such severe adverse effects of salts on plants, it has been long recognized that compositions and methods of using the same, capable of reducing such adverse influences would have great utility. Important advances in the art are the methods and compositions disclosed in U.S. Pat. Nos. 4,687,505 and 4,923,500, as well as in the foregoing mentioned U.S. patent applications.
With regard to the above mentioned patents, there is disclosed techniques for the application of certain anionic materials, or their substantially neutral water soluble salts, to soil in minute amounts, for reducing the harmful effects of salts which had accumulated in the soil from irrigation water, or which were previously present in the soil. In this manner, salts were leached from the soil by the application of a liquid, such as irrigation water. These patented compositions are effective because large areas of soil are treated, prior to planting, by the addition of the anionic materials to irrigation water or by other methods of application applied to the fields generally.
Such patented methods and compositions are highly effective in reducing soil salinity, and have proven to increase plant proliferation and quality as well as increased yield when used in crop production. Of course, other soil conditioning products are required to facilitate plant growth. Water and fertilizer are also used to help plant proliferation. Such substances help to nourish the plants, so that they can grow in a healthy and vigorous manner. However, in some situations, conventional fertilizers may not be entirely satisfactory for facilitating adequate nourishment uptake by plants. In such situations, the plants may not be able to thrive in a vigorous and healthy manner, even when conventional fertilizers are applied. In order to overcome such an inadequate nourishment problem, improved fertilizers have been developed. For a description of such an improved fertilizer, reference may be made to the foregoing U.S. patent application, Ser. No. 709,837, filed Jun. 4, 1991.
In addition to the foregoing mentioned impediments of unwanted salt and inadequate nourishment uptake, the presence of weeds and germinating weed seeds in soil, such as agricultural soils, can cause an adverse affect on plant proliferation. The weeds, and weed seeds, are often already present in the soil, prior to planting. Subsequent to planting, when irrigation water and fertilizers are applied, the weeds compete with the desired plants and, in general, can rob the desired plants of nutrients necessary for root establishment and healthy plant growth. Thus, weeds directly compete with the desired plants for the assimilation of essential nourishment, and the presence of weeds and weed seeds can cause directly the reduction of the quantity, and the quality, of the desired plants.
In addition, at the time of harvesting, the presence of the unwanted and undesirable weeds presents more difficulties for the grower. In this regard, methods have to be adopted for either removing the weeds before harvesting, or for removing the weeds from the crop, after harvesting. The weed removal is often labor intensive and, as a result, both expensive and time consuming.
In view of the foregoing, it is clear that the presence of weeds and weed seeds, in agricultural or other planting soils, can cause substantial economic loss to growers, both by reduction of yields and by increased labor costs for weed removal. Thus, it has long been recognized that compositions and methods for weed control have significant economic value. Because of the well recognized need for such compositions and methods, various herbicidal compositions have been developed. In some cases, when such a composition is applied properly to a moist soil, the liquid is converted into a gaseous in-ground fumigant for controlling both weeds and germinating weed seeds. In addition, some known herbicides have utility for controlling nematodes and other soil-borne diseases such as Rhizoctonia, which also, of course, adversely impact plant growth.
Prior known herbicides, and conventional methods of using them, are effective in reducing weed populations in soils and thereby increasing plant proliferation and plant quality, as well as increased yield. However, for some applications and under certain growing conditions, these known herbicides have not performed in an entirely satisfactory manner. Thus, for a variety of reasons, more effective herbicides for the control of weeds and weed seeds in planting soil is highly desirable.
In order to illustrate the problem, it is well recognized by those skilled in the art that some weeds, especially nutgrass, are especially difficult to control. It has been found, for example, that even after a proper application of a known herbicide to agricultural soils, the number of weeds eradicated generally does not exceed approximately 80 percent. Thus, in many instances, about 20 percent of the weeds remain in the field, after conventional herbicide treatment. Such a percentage of a remaining number of weeds, is known to be undesirable and unwanted in many agricultural growing situations. In this regard, with such a high percentage of the weeds surviving, the desired crop is often so adversely affected that the crop yield and quality are generally acceptable.
In view of the foregoing, it would be highly desirable to have an improved pesticide, which will serve as a more effective composition eradicated weeds and weed seeds to facilitate increased plant proliferation. In addition, it would be highly advantageous to facilitate significantly, the early, as well as effective, eradicated and control of weeds so that a much higher percentage of weeds can be killed. In this regard, such a product would be most effective for early and rapid weed and weed seed control, thereby facilitating early root establishment and nutrient uptake in desirable plants.
Such an improved pesticide and method of using it, would serve to control more quickly and effectively the proliferation of weeds competing for nourishment with the desired plants. With such a more rapid and effective weed controlling composition and method of using it, the desired plants can proliferate more readily, since it is important for the germination and establishment of plants to become properly nourished immediately with as little interference as possible from adverse influences, such as weeds.